Thank you for your feedback on this! Since this is a feature request for the system that sends our emails, the best way to get your voice heard is to leave your feedback in our Email specific feedback section here: https://community.constantcontact.com/t5/Email-Ideas-and-Suggestions/idb-p/emfeedback
This way other people can also vote on this to help us prioritize the features that are needed the most.
In terms of a short-term solution to this, the best option would be to store the custom fields that you wish to use in links pre-encoded. From the API perspective we intentionally do not perform and transformations on the custom fields to allow integrations and users full control over the contents and how they wish to use it.
Please let me know if you have any questions or concerns!
... View more
You are not doing anything stupid however the login credentials can be considered confusing.
Your request URI (https://api.constantcontact.com/ws/customers/impact11/contacts) is correct however your username is most likely the cause of the 401 error. Since you are testing in a browser you should be prompted for a User Name and Password.
Your User Name is going to be the combination of your API Key followed by a percent sign (%) and finally your Constant Contact Login name like so:
User Name: acbd-1234-xxxx-xxxxxxx-xxxxx%impact11
Your Password is going to be your Constant Contact account password.
Please verify that this is how you are attempting to connect and let us know if you have any other issues.
... View more